Exploration of predictors, moderators and mediators of change in parent skills training programmes for externalising behaviour problems in children – who benefits most and how do they work?

Background: A key driver for early years strategies is the reduction of oppositional and defiant behaviour in childhood to prevent a negative life course of poor educational attainment and criminality. Despite a robust evidence base, manualised parent skills training programmes (PT) for externalising behaviour problems are only effective for approximately two-thirds of families. A limited number of variables that account for variance in outcome have been discovered. Finding further predictor, moderator and mediator variables will explain who benefits most, and how change occurs. This will ensure that families receive the most appropriate treatments for their profile of needs, and services deliver the available interventions in an efficient and effective way. Objectives: A systematic review of the literature was conducted to explore progress in this area since two key meta-analyses published in 2006. A primary study was carried out to examine whether parent attachment style, parenting self-efficacy and dysfunctional parental attributions predict, moderate or mediate the levels of externalising child behaviour problems reported by parents attending the Incredible Years PT. Methods: Studies exploring variables influencing outcome in child behaviour following attendance at a manualised, evidence-based PT group for parents of children and adolescents aged 0-18 years were sought. Psychinfo, Medline, ERIC and Embase databases were searched for articles published between August 2004 and March 2013 with keywords ‘parent’, ‘child’, ‘training’, ‘indirect effects’ and ‘oppositional behaviour’ or related terms. 2853 articles were retrieved, from which 12 studies fulfilled criteria. Study quality was appraised and co-rated. A pre-post, within subjects design was conducted with 79 parents attending the Incredible Years PT delivered in a Child and Adolescent Mental Health Service. Participants completed a battery of pre-treatment questionnaires measuring attachment style, attributions, self-efficacy and child behaviour. 52 parents completed the same battery post-treatment, and missing data was carried forward in an intent to treat analysis. Data was analysed using multiple regression techniques, and mediation and moderated mediation analyses. Results: The recent evidence base is populated by secondary analyses of intervention RCTs, and less robust non RCTs. The selection of maternal mood, parenting stress, parenting style and child demographics dominate, and the exploration of unique variables is limited. Significant findings are mixed and add no new variables to our understanding. Significant changes in parenting self-efficacy and dysfunctional attributions were found post-treatment, and attachment style remained stable. A main treatment effect size of d=.3 was estimated, and a significant number of children fell below sub-clinical levels of problem behaviour (n=13, 15.7%). Baseline child-responsible attributions and self-efficacy accounted for up to 40% of the variance in baseline child behaviour. Attachment style did not contribute significantly to the model, but moderated parent-causal attributions. Post-treatment, attachment avoidance had a moderating effect on self-efficacy and child-responsible attributions, and a significant direct effect on outcome. The indirect effect of parental-attributions on child behaviour through self-efficacy was moderated by attachment avoidance which reduced the number of significant paths. Conclusions: The call for PT studies delivered with fidelity in real world settings has been recognised, and more sophisticated statistical models of mediation are being adopted. There remains an exhaustive list of novel potential variables that future research needs to select and explore in primary research designs. An evidence based PT is achieving statistically and clinically significant results for children referred for problem behaviour. Dysfunctional parent attributions and self-efficacy are predictors of both pre- and post-treatment levels of child behaviour, which could be screened for in the referral process. The evidence for a direct and indirect role of attachment style on parent training outcomes adds a new candidate variable to the literature that warrants further exploration